Visual light communication (VLC) is a data communication medium that uses visible light between 400 THz (780 nm) and 800 THz (375 nm) as an optical carrier for data transmission and illumination. It uses fast pulses of light to transmit information. Light emitting diodes (LEDs) are one type of light that can be used in VLC. LEDs can be turned on and off quickly and perceived as a continuous beam of light. This is because the reaction time of the typical LED is less than 1 microsecond, which cannot be detected by the human eye. The change from an “on” state to an “off” state in high frequencies enables data transmission. “On” states and “off” states (represented as “1” and “0” respectively) can be encoded as data. Signal processing can be used to process that encoded data into information useable in a variety of contexts.